JP7543983B2 - Structural Displacement Measurement System - Google Patents

Description

The present invention relates to a structural displacement measurement system, and more particularly to a structural displacement measurement system that can be suitably used to detect the displacement of a structure.

The vertical displacement of the bridge superstructure is measured during construction management of bridges during construction and during maintenance management of bridges after they are put into service. This measurement is not only performed using contact displacement meters, but also non-contact measurement using a laser irradiation device (Patent Document 1).

A monitoring system is also known that measures the displacement of structures such as bridges by monitoring measurement data obtained using an acceleration sensor (Patent Document 2).

JP 2000-249548 A JP 2019-215203 A

However, the technology described in Patent Document 1 measures bridge displacement from the outside by installing a laser light source on the ground or on scaffolding installed outside the bridge. Therefore, the displacement measured includes the amount of displacement of the entire bridge relative to the ground, and detecting the displacement of a specific part of the bridge requires time-consuming corrections that take these amounts of displacement into account. In addition, if the measurement target is localized deflection displacement, such as in the middle of the bridge, special scaffolding is required to install the laser light source, and because the laser light source is outside the bridge, the distance to the measured point must be long, which creates problems such as large accuracy errors in the obtained displacement data, such as angle errors. In addition, no consideration is given to understanding the displacement characteristics of the entire bridge superstructure.

In addition, the technology disclosed in Patent Document 2 monitors the displacement of a structure based on acceleration data obtained from an acceleration sensor, so it is necessary to obtain the change in acceleration data over time by time integration, and since it is necessary to continue obtaining the acceleration data for a certain period of time, or even all the time, the time burden of monitoring the measurements is large.

The present invention was made in consideration of these points, and aims to provide a structure displacement measurement system that can measure the deflection displacement of a structure with a small time burden and high accuracy.

The present invention is an invention that solves the above problems, and is, for example, the following structural displacement measurement system.

That is, a first aspect of the structure displacement measurement system according to the present invention is a structure displacement measurement system for measuring the displacement of a portion on a structure, comprising: a laser beam irradiation means having a laser oscillator for emitting laser light and arranged on the structure; a laser angle adjustment means for adjusting the emission angle of the laser beam emitted from the laser beam irradiation means to a predetermined angle; a light receiving unit for receiving the laser beam emitted from the laser beam irradiation means and capable of detecting the receiving position of the laser beam; a target member arranged on the structure at a predetermined distance from the laser beam irradiation means in the emission direction of the laser beam emitted from the laser beam irradiation means; and a displacement amount calculation means capable of calculating the amount of displacement in a predetermined direction from the first time to the second time of a portion on the structure where the target member is placed, based on difference information between first position information about a light receiving position obtained when the laser light emitted from the laser light emitting means and adjusted to a predetermined angle by the laser angle adjustment means is received by the light receiving unit of the target member, and second position information about a light receiving position obtained when the laser light emitted from the laser light emitting means at a second time after the first time and adjusted to the predetermined angle by the laser angle adjustment means is received by the light receiving unit of the target member.

A second aspect of the structure displacement measurement system according to the present invention is a structure displacement measurement system for measuring the displacement of a portion on a structure, comprising: a laser beam emitting means arranged on the structure, the laser beam emitting means having a laser oscillator for emitting laser beam; a laser angle detection means for detecting the emission angle of the laser beam emitted from the laser beam emitting means; a reflecting member for reflecting the laser beam, arranged on the structure at a predetermined distance from the laser beam emitting means in the emission direction of the laser beam emitted from the laser beam emitting means; a reflected beam receiving unit arranged close to the laser beam emitting means on the structure, for receiving the reflected beam of the laser beam reflected by the reflecting member and capable of detecting the receiving position of the reflected beam; and a laser beam emitting angle information obtained by detection by the laser angle detection means and a laser beam receiving angle information of the reflected beam received by the reflected beam receiving unit. and a displacement amount calculation means capable of calculating the amount of displacement in a predetermined direction of a portion on the structure where the reflecting member is disposed based on position information about the light receiving position, the displacement amount calculation means being capable of calculating the amount of displacement in a predetermined direction of a portion on the structure where the reflecting member is disposed from the first time to the second time based on emission angle difference information between a first emission angle obtained by detecting the emission angle of the laser light emitted from the laser light emitting means at a first time with the laser angle detection means and a second emission angle obtained by detecting the emission angle of the laser light emitted from the laser light emitting means at a second time after the first time with the laser angle detection means, and position information about the light receiving position obtained when the laser light emitted at the second time is reflected by the reflecting member and received by the reflected light receiving unit.

（前記関係式１中、
Ｌ１は、１番目のレーザー光照射手段の配置位置と１番目のターゲット部材の配置位置との間の、前記所定方向と直交する一定の方向における距離であり、
Ｌｉは、ｉ番目のレーザー光照射手段の配置位置とｉ番目のターゲット部材の配置位置との間の、前記所定方向と直交する一定の方向における距離であり、
Ｍｉは、ｉ番目のターゲット部材の配置位置とｉ＋１番目のレーザー光照射手段の配置位置との間の、前記所定方向と直交する一定の方向における距離である）
を満たすように配置され、前記変位量算出手段は、第１の時間に第（ｎ－１）番目の前記レーザー光照射手段から前記レーザー角度調整手段で所定角度に調整されて出射したレーザー光が前記第（ｎ－１）番目の前記ターゲット部材の前記受光部に受光されて得られる受光位置についての第１位置情報と、前記第１の時間後の第２の時間に前記第（ｎ－１）番目の前記レーザー光照射手段から前記レーザー角度調整手段で前記所定角度に調整されて出射したレーザー光が前記第（ｎ－１）番目の前記ターゲット部材の前記受光部に受光されて得られる受光位置についての第２位置情報との差分情報に基づいて、前記第（ｎ－１）番目の前記ターゲット部材が配置された前記構造物上の部位の前記第１の時間から前記第２の時間までの第（ｎ－１）構造変位量を算出可能であり、また、前記第１の時間に第ｎ番目の前記レーザー光照射手段から前記レーザー角度調整手段で所定角度に調整されて出射したレーザー光が前記第ｎ番目の前記ターゲット部材の前記受光部に受光されて得られる受光位置についての第１位置情報と、前記第１の時間後の第２の時間に前記第ｎ番目の前記レーザー照射手段から前記レーザー角度調整手段で前記所定角度に調整されて出射したレーザー光が前記第ｎ番目の前記ターゲット部材の前記受光部に受光されて得られる受光位置についての第２位置情報との差分情報に基づいて、前記第ｎ番目の前記ターゲット部材が配置された前記構造物上の部位の前記第１の時間から前記第２の時間までの第ｎ構造変位量を算出可能であることを特徴とする構造物変位計測システムである。 A third aspect of the structure displacement measurement system according to the present invention is a structure displacement measurement system for measuring the displacement of a portion on a structure, comprising: laser light irradiating means having a laser oscillator unit for emitting laser light, and arranged on the structure; a light receiving unit for receiving the laser light emitted from the laser light irradiating means and capable of detecting a receiving position of the laser light, and n (n≧2) target members arranged on the structure at a predetermined distance from the laser light irradiating means in the emission direction of the laser light emitted from the laser light irradiating means; laser angle adjustment means for adjusting the emission angle of the laser light emitted from each of the n laser light irradiating means to a predetermined angle; and a displacement amount calculation means capable of calculating a displacement amount in a predetermined direction of a portion on the structure where each of the n target members is arranged, based on position information on the light receiving positions obtained by each of the light receiving units of the n target members, wherein a direction from a kth (1≦k≦n) laser light irradiation means to a kth (1≦k≦n) target member among the n laser light irradiation means and the n target members is an emission direction of a laser light emitted from the kth laser light irradiation means, and a distance Sn between a first laser light irradiation means and the nth target member in a certain direction perpendicular to the predetermined direction is expressed by the following relational expression 1, i.e.,

(In the above Relational Formula 1,
L1 is the distance between the arrangement position of the first laser light irradiation means and the arrangement position of the first target member in a certain direction perpendicular to the predetermined direction,
Li is the distance between the arrangement position of the i-th laser light irradiation means and the arrangement position of the i-th target member in a certain direction perpendicular to the predetermined direction,
Mi is the distance between the position of the i-th target member and the position of the (i+1)-th laser light irradiation means in a certain direction perpendicular to the predetermined direction.
the (n-1)th target member is disposed so as to satisfy the above condition, and the displacement amount calculation means calculates a (n-1)th structural displacement from the first time to the second time of a portion on the structure where the (n-1)th target member is disposed, based on difference information between first position information on a light receiving position obtained when a laser beam adjusted to a predetermined angle by the laser angle adjustment means and emitted from the (n-1)th laser light irradiating means at a first time is received by the light receiving unit of the (n-1)th target member, and second position information on a light receiving position obtained when a laser beam adjusted to the predetermined angle by the laser angle adjustment means and emitted from the (n-1)th laser light irradiating means at a second time after the first time is received by the light receiving unit of the (n-1)th target member. and is capable of calculating an n-th structural displacement amount from the first time to the second time of a portion on the structure where the n-th target member is located, based on difference information between first position information about a light-receiving position obtained when the laser light emitted from the n-th laser light irradiating means after being adjusted to a predetermined angle by the laser angle adjustment means at the first time is received by the light-receiving unit of the n-th target member, and second position information about a light-receiving position obtained when the laser light emitted from the n-th laser irradiating means after being adjusted to the predetermined angle by the laser angle adjustment means at a second time after the first time is received by the light-receiving unit of the n-th target member.

Here, "distance Sn in a fixed direction perpendicular to the specified direction" refers to the distance from the first laser light emitting means to the nth target member in a fixed direction perpendicular to the direction in which displacement is measured. For example, when calculating the vertical displacement of a part on the superstructure of a bridge, it refers to the distance in a fixed direction perpendicular to the vertical direction, i.e., in a fixed horizontal direction. In this case, even if the laser light emitting means and the target member that receives the laser light are positioned at an angle from a fixed horizontal direction, "distance Sn in a fixed direction perpendicular to the specified direction" refers to the distance in that fixed horizontal direction.

In addition, when calculating the vertical displacement of a part on the superstructure of a bridge, a certain horizontal direction that is a "certain direction perpendicular to the specified direction" can be, for example, the bridge axis direction of the bridge, and in this case, the distribution of the vertical displacement of the superstructure of the bridge can be calculated for a specified range in the bridge axis direction of the bridge.

In addition, although it is stated that the relational expression 1 is "arranged so as to satisfy," it goes without saying that even if the relational expression 1 is not satisfied due to slight misalignment or error of the laser irradiation means or target member, as long as the effect of the present invention is within the scope of the third aspect of the structure displacement measurement system according to the present invention.

（前記関係式２中、
Ｌ１は、１番目のレーザー光照射手段の配置位置と１番目の反射部材の配置位置との間の、前記所定方向と直交する一定の方向における距離であり、
Ｌｉは、ｉ番目のレーザー光照射手段の配置位置とｉ番目の反射部材の配置位置との間の、前記所定方向と直交する一定の方向における距離であり、
Ｍｉは、ｉ番目の反射部材の配置位置とｉ＋１番目のレーザー光照射手段の配置位置との間の、前記所定方向と直交する一定の方向における距離である）
を満たすように配置され、前記変位量算出手段は、第１の時間に第（ｎ－１）番目の前記レーザー光照射手段から出射したレーザー光の出射角度を前記レーザー角度検出手段で検出して得られる第１出射角度と、前記第１の時間後の第２の時間に前記第（ｎ－１）番目の前記レーザー光照射手段から出射したレーザー光の出射角度を前記レーザー角度検出手段で検出して得られる第２出射角度との出射角度差分情報、および前記第２の時間に前記第（ｎ－１）番目の前記レーザー光照射手段から出射したレーザー光が前記第（ｎ－１）番目の前記反射部材で反射して前記第（ｎ－１）番目の前記反射光受光部に受光されて得られる受光位置についての位置情報に基づいて、前記第（ｎ－１）番目の前記反射部材が配置された前記構造物上の部位の前記第１の時間から前記第２の時間までの第（ｎ－１）構造変位量を算出可能であり、また、前記第１の時間に前記第ｎ番目の前記レーザー光照射手段から出射したレーザー光の出射角度を前記レーザー角度検出手段で検出して得られる第１出射角度と、前記第１の時間後の第２の時間に前記第ｎ番目の前記レーザー光照射手段から出射したレーザー光の出射角度を前記レーザー角度検出手段で検出して得られる第２出射角度との出射角度差分情報、および前記第２の時間に前記第ｎ番目の前記レーザー光照射手段から出射したレーザー光が前記第ｎ番目の前記反射部材で反射して前記第ｎ番目の前記反射光受光部に受光されて得られる受光位置についての位置情報に基づいて、前記第ｎ番目の前記反射部材が配置された前記構造物上の部位の前記第１の時間から前記第２の時間までの第ｎ構造変位量を算出可能であることを特徴とする構造物変位計測システムである。 A fourth aspect of the structure displacement measurement system according to the present invention is a structure displacement measurement system for measuring the displacement of a portion on a structure, the system comprising: laser light irradiating means having a laser oscillator for emitting laser light and arranged on the structure; a reflecting member for reflecting the laser light, arranged on the structure at a predetermined distance from the laser light irradiating means in the emission direction of the laser light emitted from the laser light irradiating means; and n (n≧2) reflected light receiving units arranged close to each of the laser light irradiating means on the structure, receiving reflected light of the laser light reflected by the reflecting member and capable of detecting a receiving position of the reflected light, the system comprising: laser angle detection means for detecting an emission angle of the laser light emitted from each of the n laser light irradiating means; and a displacement amount calculation means capable of calculating a displacement amount in a predetermined direction of a portion on a structure at which each of the n reflecting members is arranged, based on emission angle information of each of the laser beams emitted from the n laser beam emitting means, which is obtained by detection by the emitting means, and position information on a receiving position of the reflected light, which is obtained by each of the n reflected light receiving units, wherein a direction from a k-th (1≦k≦n) laser beam emitting means to a k-th (1≦k≦n) reflecting member among the n laser beam emitting means and the n reflecting members is an emission direction of a laser beam emitted from the k-th laser beam emitting means, and a distance Sn between a first laser beam emitting means and the n-th reflecting member in a certain direction perpendicular to the predetermined direction is expressed by the following Relational Formula 2, i.e.,

(In the above-mentioned Relational Formula 2,
L1 is the distance between the arrangement position of the first laser light irradiation means and the arrangement position of the first reflecting member in a certain direction perpendicular to the predetermined direction,
Li is the distance between the position of the i-th laser light irradiation means and the position of the i-th reflecting member in a certain direction perpendicular to the predetermined direction,
Mi is the distance between the position of the i-th reflecting member and the position of the (i+1)-th laser light irradiating means in a certain direction perpendicular to the predetermined direction.
the displacement amount calculation means calculates a (n-1)th structural displacement from the first time to the second time of a portion on the structure where the (n-1)th reflecting member is disposed, based on emission angle difference information between a first emission angle obtained by detecting an emission angle of the laser light emitted from the (n-1)th laser light emitting means at a first time with the laser angle detection means and a second emission angle obtained by detecting an emission angle of the laser light emitted from the (n-1)th laser light emitting means at a second time after the first time with the laser angle detection means, and position information on a light receiving position obtained by the laser light emitted from the (n-1)th laser light emitting means at the second time being reflected by the (n-1)th reflecting member and received by the (n-1)th reflected light receiving unit. and is capable of calculating an n-th structural displacement amount from the first time to the second time of a portion on the structure at which the nth reflecting member is disposed, based on emission angle difference information between a first emission angle obtained by detecting with the laser angle detection means the emission angle of the laser light emitted from the nth laser light emitting means at the first time and a second emission angle obtained by detecting with the laser angle detection means the emission angle of the laser light emitted from the nth laser light emitting means at a second time after the first time, and position information on a light receiving position obtained when the laser light emitted from the nth laser light emitting means at the second time is reflected by the nth reflecting member and received by the nth reflected light receiving unit.

Here, "distance Sn in a certain direction perpendicular to the specified direction" refers to the distance from the first laser light emitting means to the nth reflecting member in a certain direction perpendicular to the direction in which the displacement is measured. For example, when calculating the vertical displacement of a part on the superstructure of a bridge, it refers to the distance in a certain direction perpendicular to the vertical direction, that is, in a certain horizontal direction. In this case, even if the laser light emitting means and the reflecting member that reflects the laser light are arranged at an angle from a certain horizontal direction, "distance Sn in a certain direction perpendicular to the specified direction" refers to the distance in that certain horizontal direction.

In addition, when calculating the vertical displacement of a part on the superstructure of a bridge, a certain horizontal direction that is a "certain direction perpendicular to the specified direction" can be, for example, the bridge axis direction of the bridge, and in this case, the distribution of the vertical displacement of the superstructure of the bridge can be calculated for a specified range in the bridge axis direction of the bridge.

In addition, although it is stated that the above-mentioned relational expression 2 is "arranged so as to satisfy," it goes without saying that even if the above-mentioned relational expression 2 is not satisfied due to some misalignment or error in the positioning of the laser irradiation means or the reflecting member, as long as the effect of the present invention is within the scope of the fourth aspect of the structure displacement measurement system according to the present invention.

In addition, as a fifth aspect, the displacement amount in the specified direction that can be calculated by the displacement amount calculation means of the structure displacement measurement system of the first aspect may be the displacement amount of the vertical component of the part on the structure where the target member is placed.

In a sixth aspect, the displacement in the specified direction that can be calculated by the displacement amount calculation means of the structure displacement measurement system of the second aspect may be the displacement amount of the vertical component of the portion on the structure where the reflecting member is arranged.

In a seventh aspect, the (n-1) structural displacement amount and the n structural displacement amount that can be calculated by the displacement amount calculation means of the structural displacement measurement system of the third aspect may be the displacement amount of the vertical component of the portion on the structure where the target member is placed.

In an eighth aspect, the (n-1) structural displacement amount and the n structural displacement amount that can be calculated by the displacement amount calculation means of the structural displacement measurement system of the fourth aspect may be the displacement amount of the vertical component of the portion on the structure where the reflecting member is arranged.

As a ninth aspect, in the structure displacement measurement system of the fifth aspect, the structure may be a superstructure of a bridge, the superstructure having a main girder, the laser light emitting means is disposed on the main girder of the superstructure, the target member is installed on one main girder that is the same as the main girder and is spaced a predetermined distance from the laser light emitting means in the longitudinal direction of the main girder, and the displacement amount calculation means may be configured to calculate the displacement amount of the vertical component of the portion on the main girder where the target member is disposed.

In this application, the term "main girder" refers to the main structural member of the superstructure of the bridge, which extends in the bridge axis direction of the bridge and supports the vertical load applied to the superstructure of the bridge and transmits it to the substructure.

In addition, the longitudinal direction of the main girder means the tangential direction when the main girder is bent. Similar descriptions in other parts of this application shall be interpreted in the same manner.

In addition, as a tenth aspect, in the structure displacement measurement system of the sixth aspect, the structure may be a superstructure of a bridge, the superstructure having a main girder, the laser light emitting means is disposed on the main girder of the superstructure, the reflecting member is installed on one main girder that is the same as the main girder and is spaced a predetermined distance from the laser light emitting means in the longitudinal direction of the main girder, and the displacement amount calculation means may be configured to be capable of calculating the displacement amount of the vertical component of the portion on the main girder where the reflecting member is disposed.

In an eleventh aspect, in the structure displacement measurement system of the seventh aspect, the structure may be a superstructure of a bridge, the superstructure having a main girder, the n laser light emitting means are all arranged on one of the main girders of the superstructure, each of the n target members is arranged on the same one of the main girders at a predetermined distance in the longitudinal direction of the same one of the main girders from each of the n laser light emitting means, and the displacement amount calculation means may be configured to calculate the displacement amount of the vertical component of the portion on the main girder where the target member is arranged.

In addition, as a twelfth aspect, in the structure displacement measurement system of the eighth aspect, the structure may be a superstructure of a bridge, the superstructure having a main girder, the n laser light emitting means are all arranged on one of the main girders of the superstructure, each of the n reflecting members is arranged on the same one of the main girders at a predetermined distance in the longitudinal direction of the same one of the main girders from each of the n laser light emitting means, and the displacement amount calculation means may be configured to calculate the displacement amount of the vertical component of the portion on the main girder where the reflecting member is arranged.

In addition, as a thirteenth aspect, in the structure displacement measurement system of the eleventh or twelfth aspect, the first of the n laser light irradiation means may be disposed near a support of the substructure of the bridge.

In this way, by placing the first laser light irradiation means near the support of the bridge's substructure, where displacement is relatively small, it becomes possible to accurately calculate the absolute displacement amount at a specific part of the bridge at any distance from the position where the first laser light irradiation means is placed.

In addition, as a fourteenth aspect, in the structural displacement measurement system of the ninth or eleventh aspect, the laser light irradiation means and the target member may be installed on the underside of the same main girder.

In addition, as a fifteenth aspect, in the structural displacement measurement system of the tenth or twelfth aspect, the laser light irradiation means and the reflecting member may be installed on the underside of the same main girder.

As a sixteenth aspect, in the structure displacement measurement system of the thirteenth aspect, the distance Sn may be approximately equal to the entire longitudinal length of the same main girder, and this configuration makes it possible to grasp the displacement distribution over the entire length of the bridge on which the system is mounted. In other words, "the distance Sn is approximately equal to the entire longitudinal length of the same main girder" means that the distance Sn has a length necessary to enable the amount of displacement of the vertical component to be estimated with a predetermined degree of accuracy or higher over each part of the entire longitudinal length of the same main girder.

As a seventeenth aspect, in the structure displacement measurement system according to any one of the first to sixteenth aspects, the displacement amount calculation means may be an externally connectable computer.

The laser light irradiating means may be configured to include a tilt sensor as a means for detecting the emission angle of the emitted laser light.

The present invention provides a structure displacement measurement system that can measure the deflection displacement of a structure with a small time burden and high accuracy.

FIG. 1 is a side view illustrating a structure displacement measurement system 10 according to a first embodiment of the present invention. FIG. 1 is a schematic diagram of a structure displacement measurement system 10 according to the first embodiment, in which general equipment used in actual measurements is also shown. FIG. 1 is a block diagram of a structure displacement measurement system 10 according to the first embodiment, to which general equipment used in actual measurement is added. A side view showing a state in which a relative vertical displacement v (a difference in vertical position coordinates between the installation position (position P2) of the reflecting member 14 on the underside of the main girder 104 and the installation position (position P1) of the laser light irradiation means 12 on the underside of the main girder 104) occurs at position P2, which is the installation point of the reflecting member 14 on the main girder 104 of the superstructure 102 of the bridge 100. FIG. 13 is a side view diagrammatically illustrating a structure displacement measuring system 20 according to a second embodiment of the present invention. FIG. 1 is a schematic diagram of a structure displacement measurement system 20 according to the second embodiment, in which general equipment used in actual measurements is also shown. FIG. 1 is a block diagram of a structure displacement measurement system 20 according to the second embodiment, to which general equipment used in actual measurement is added. FIG. 1 is a side view showing a state in which a relative vertical displacement v (a difference in vertical position coordinates between the installation position (position P2) of the target 24 on the underside of the main girder 104 and the installation position (position P1) of the laser light irradiation means 22 on the underside of the main girder 104) occurs at position P2, which is the installation point of the target 24 on the underside of the main girder 104 of the superstructure 102 of the bridge 100. FIG. 13 is a bottom view illustrating a structure displacement measurement system 40 according to a third embodiment of the present invention. A vertical cross-sectional view of the superstructure 102 of the bridge 100 to which the structure displacement measurement system 40 according to the third embodiment is applied (a cross-sectional view cut vertically along line XX in FIG. 9 ). FIG. 11 is an enlarged vertical cross-sectional view showing a portion XI of FIG. FIG. 1 is a side view showing a case where there are four sets of displacement measuring means 42 (n=4), and shows a state where relative vertical displacements v1, v2, v3, and v4 occur at positions P11, P12, P13, and P14, which are installation points of targets 24 on the main girder 104 of the superstructure 102 of the bridge 100, with respect to the emission point of the laser light Lh. FIG. 1 is a side view showing a schematic diagram of deformation of the entire superstructure 102 of a bridge 100 in the vertical direction. FIG. 13 is a side view diagrammatically illustrating a structure displacement measuring system 50 according to a fourth embodiment of the present invention. FIG. 13 is a side view diagrammatically illustrating a structure displacement measuring system 60 according to a fifth embodiment of the present invention.

Below, an embodiment of the structure displacement measurement system according to the present invention will be described in detail with reference to the drawings.

(1) First embodiment Fig. 1 is a side view showing a structure displacement measurement system 10 according to a first embodiment of the present invention, Fig. 2 is a schematic system configuration diagram of the structure displacement measurement system 10 according to the first embodiment with the addition of general instruments used when performing actual measurement, and Fig. 3 is a block diagram of the structure displacement measurement system 10 according to the first embodiment with the addition of general instruments used when performing actual measurement. Fig. 1 shows a state in which no load is applied to the main girder 104, and shows a state in which no deflection occurs in the main girder 104.

The structure displacement measurement system 10 according to the first embodiment is a structure displacement measurement system that measures the difference in position coordinates between two predetermined positions P1 and P2 of the superstructure 102 of the bridge 100 in the vertical direction.

As shown in Fig. 1, the structure displacement measurement system 10 according to the first embodiment comprises a laser light emitting means 12 and a reflecting member 14. Both the laser light emitting means 12 and the reflecting member 14 are installed on the underside of the main girder 104 of the superstructure 102 of the bridge 100, with the laser light emitting means 12 installed at position P1 and the reflecting member 14 installed at position P2. In detail, in Fig. 1, the laser light emitting means 12 and the reflecting member 14 are installed at positions such that when the laser light L is irradiated from the laser light emitting means 12 so as to hit the vicinity of the center of the reflecting portion 14A of the reflecting member 14, the direction of the laser light L is in the longitudinal direction of the main girder 104.

The laser light emitting means 12 is equipped with a laser oscillator 12A that oscillates and emits laser light L. The laser light emitting means 12 is also equipped with a known tilt sensor (not shown) as a laser light emission angle detection means that detects the emission angle (e.g., the angle with respect to the horizontal plane) of the emitted laser light L. Furthermore, the laser light emitting means 12 is equipped with a laser receiving element (not shown) provided adjacent to the laser oscillator 12A of the laser light emitting means.

This laser receiving element, the laser light emitting means 12, and the reflecting portion 14A that is part of the reflecting member 14 constitute what is called a laser displacement sensor. In other words, the laser light L irradiated to the reflecting member 14 is reflected by the reflecting portion 14A of the reflecting member 14, and the reflected light R that returns can be detected based on the intensity of the light receiving spot received by the laser receiving element, thereby making it possible to measure the distance from the laser oscillation portion 12A to the reflecting member 14.

Therefore, the vertical displacement can be measured using the principle of triangulation based on the laser light emission angle information obtained by the tilt sensor, which is the laser light emission angle detection means, and the distance information from the laser oscillation unit 12A to the reflection unit 14A of the laser light irradiation means 12 obtained by the laser displacement sensor.

In other words, for example, the above-mentioned laser light emission angle information and distance information are measured when the main girder is not under load (first time), and then, for example, the same laser light emission angle information and distance information are measured when the main girder is under load (second time after the first time), and the amount of displacement in the vertical direction from the unloaded state can be calculated based on the difference information between these.

The reflecting portion 14A of the reflecting member 14, which reflects the laser light L irradiated from the laser light irradiating means 12, is constructed so that the reflective surface is flat, using a material that can sufficiently reflect the laser light L irradiated from the laser light irradiating means 12. Specifically, for example, it may be constructed by attaching a white reflective sheet to a flat surface, or it may be constructed of a white reflecting plate.

The laser light irradiation means 12 is externally equipped with a communication device 16 that can be connected to the Internet 200, and is configured so that electrical signals can be exchanged with the laser light irradiation means 12 using a computer 18 from an office or the like away from the site. The computer 18 is equipped with a displacement amount calculation unit 18A and an instruction unit 18B, and the displacement amount calculation unit 18A and the instruction unit 18B are configured to be executed by the hardware and software of the computer 18. The electrical signals given to the laser light irradiation means 12 include an electrical signal for a laser light oscillation command, an electrical signal for turning the power of the laser light irradiation means 12 on and off, etc., and the electrical signals sent from the laser light irradiation means 12 to the computer 18 include an electrical signal for the distance to the reflecting member 14 measured by the laser light irradiation means 12, and an electrical signal for the irradiation angle of the laser light L measured by the laser light irradiation means 12, etc.

The communication device 16 may be modularized and integrated into the laser light irradiation means 12.

Next, a specific measurement method using the structure displacement measurement system 10 according to the first embodiment will be described. Figure 4 is a side view showing a state in which a relative vertical displacement v (the difference in vertical position coordinates between the installation position (position P2) of the reflecting member 14 on the underside of the main girder 104 and the installation position (position P1) of the laser light irradiation means 12 on the underside of the main girder 104) occurs at position P2, which is the installation point of the reflecting member 14 on the main girder 104 of the superstructure 102 of the bridge 100, at the time when the main girder is under load (second time) compared to the time when the main girder is under load (first time). A case in which measurement is performed using the structure displacement measurement system 10 in this state will be described.

The laser light emitting means 12 irradiates the reflecting member 14 with laser light L, and measures the distance D from the laser light oscillation point 12A1 of the laser light emitting means 12 to the light receiving point (reflection point) 14A1 of the reflecting member 14, and the angle θ of the laser light L irradiated by the laser light emitting means 12 with respect to the horizontal plane using the laser displacement sensor and the tilt sensor as the laser light emission angle detection means.

Then, the measured distance information (distance D from the laser light emission point 12A1 of the laser light emitting means 12 to the light receiving point (reflection point) 14A1 of the reflecting member 14) and angle information (angle θ of the laser light L irradiated by the laser light irradiating means 12 with respect to the horizontal plane) are input to the displacement amount calculation unit 18A, which calculates the relative vertical displacement v at the position P2 where the reflecting member 14 is installed (the difference in vertical position coordinates of the installation position P2 of the reflecting member 14 on the underside of the main girder 104 relative to the installation position P1 of the laser light irradiating means 12 on the underside of the main girder 104) as the displacement amount.

Specifically, first, an electrical signal (an electrical signal for turning on the power supply of the laser light irradiation means 12, and an electrical signal for causing the laser light irradiation means 12 to irradiate the laser light L) is input from the instruction unit 18B of the computer 18 to the laser light irradiation means 12 via the Internet 200 and the communication device 16, and the laser light irradiation means 12 irradiates the laser light L to the reflecting member 14.

The laser light L irradiated from the laser light irradiating means 12 to the reflecting member 14 is reflected by the reflecting portion 14A of the reflecting member 14 as reflected light R, returns to the laser light irradiating means 12, and is received by a reflected light receiving portion (not shown) provided adjacent to the laser oscillation portion 12A of the laser light irradiating means 12. Data on the reflected light R received by the reflected light receiving portion is transmitted as an electrical signal by the communication device 16. The transmitted electrical signal is sent via the Internet 200 and received by the displacement amount calculation portion 18A. The displacement amount calculation portion 18A, which has received the data on the reflected light R, calculates the distance D from the laser light oscillation point 12A1 of the laser light irradiating means 12 to the receiving point (reflection point) 14A1 of the reflecting member 14 based on the data on the reflected light R received by the reflected light receiving portion, and stores the distance information data in the displacement amount calculation portion 18A.

The tilt sensor mounted on the laser light emitting means 12 transmits data on the angle θ of the laser light L irradiated to the reflecting member 14 relative to the horizontal plane as an electrical signal via the communication device 16. The transmitted electrical signal is sent via the Internet 200 and received by the computer 18. The computer 18 receives the data on the angle θ of the laser light L relative to the horizontal plane, and calculates the angle θ of the laser light L irradiated to the reflecting member 14 by the laser light emitting means 12 relative to the horizontal plane based on that data, and outputs this angle θ to the displacement amount calculation unit 18A as angle information data.

The displacement amount calculation unit 18A calculates the above-mentioned relative vertical displacement v at the position P2 where the reflecting member 14 is installed based on the input distance information data and angle information data. Specifically, the displacement amount calculation unit 18A calculates the above-mentioned relative vertical displacement v by (the above-mentioned relative vertical displacement v) = D × tan θ using, for example, the distance D, which is the distance information data, and the angle θ, which is the angle information data.

As described above, the structure displacement measurement system 10 according to the first embodiment is placed on the main girder 104 of the bridge 100, which is the measurement target, and is therefore able to measure the relative vertical displacement v described above with high precision. Furthermore, since it is only necessary to perform measurements at the first time and the second time, and there is no need to continue measuring at all times, the time burden of measurement is small.

In the structure displacement measurement system 10 according to the first embodiment, the displacement calculation unit 18A is configured with the hardware and software of a computer 18 arranged outside the bridge, and is configured so that input data can be input to the displacement calculation unit 18A via wired or wireless connection. However, any device that can input the above-mentioned distance information data and angle information data and calculate the displacement amount can be used as the displacement calculation unit 18A, and the displacement calculation unit 18A may be provided on the bridge itself.

In the above explanation of the structure displacement measurement system 10 according to the first embodiment, as shown in Figures 1 and 4, a case has been described in which the structure displacement measurement system 10 is installed on the underside of the main girder 104 of the superstructure 102 of the bridge 100, but the location where the structure displacement measurement system 10 according to the first embodiment can be installed is not limited to the underside of the main girder of the bridge superstructure. Furthermore, the measurement target is not limited to the difference in vertical position coordinates between two specified positions P1 and P2 of the superstructure 102 of the bridge 100.

In the structure displacement measurement system 10 according to the first embodiment, an instruction signal is input from the instruction unit 18B of the computer 18 to the laser light irradiation means 12 via the Internet 200 and the communication device 16, but an instruction signal may also be input directly from the instruction unit 18B to the laser light irradiation means 12 via a wired or wireless connection.

(2) Second embodiment Fig. 5 is a side view showing a structure displacement measurement system 20 according to a second embodiment of the present invention, Fig. 6 is a system schematic diagram of the structure displacement measurement system 20 according to the second embodiment to which general instruments used in actual measurement are also added, and Fig. 7 is a block diagram of the structure displacement measurement system 20 according to the second embodiment to which general instruments used in actual measurement are also added. Fig. 5 shows a state in which no load is applied to the main girder 104 (a state in which no deflection occurs in the main girder 104), and this state will be referred to as the reference state hereinafter.

The structure displacement measurement system 20 according to the second embodiment is a structure displacement measurement system that measures the difference in position coordinates between two specific positions P1 and P2 of the superstructure 102 of the bridge 100 in the vertical direction, and in this respect is similar to the structure displacement measurement system 10 according to the first embodiment.

The structure displacement measurement system 20 according to the second embodiment includes a laser light irradiation means 22 and a target 24, as shown in FIG. 5. Both the laser light irradiation means 22 and the target 24 are installed on the underside of the main girder 104 of the superstructure 102 of the bridge 100, with the laser light irradiation means 22 installed at position P1 and the target 24 installed at position P2. In detail, in the reference state shown in FIG. 5 (a state in which no load is applied to the main girder 104 and the underside of the main girder 104 is a horizontal plane), when the laser light irradiation means 22 irradiates laser light Lh so that it hits the center of the light receiving portion 24A of the target 24, the laser light irradiation means 22 and the target 24 are installed at positions such that the direction of the laser light Lh is the longitudinal direction of the main girder 104.

The laser light irradiation means 22 is equipped with a laser oscillation unit 22A that oscillates the laser light Lh and irradiates the target object, and has the function of irradiating the target object with the laser light Lh. The laser light irradiation means 22 is also equipped with a tilt sensor (not shown) and a servo mechanism (not shown) that controls the irradiation direction of the laser light Lh irradiated from the laser oscillation unit 22A so that it is always the same as the irradiation direction in the reference state (so that it is horizontal in Figure 5 and Figure 8 described later).

The laser light irradiation means 22 is externally equipped with a communication device 26 that can be connected to the Internet 200, and is configured so that electrical signals can be exchanged between the laser light irradiation means 22 and the computer 30 from an office or the like away from the site. The computer 30 is equipped with a displacement amount calculation unit 30A and an instruction unit 30B, which are configured to be executed by the hardware and software of the computer 30. The electrical signals given to the laser light irradiation means 22 include an electrical signal for a laser light oscillation command, an electrical signal for turning the power of the laser light irradiation means 22 on and off, etc.

The communication device 26 may be modularized and integrated into the laser light irradiation means 22.

The target 24 is equipped with a light receiving unit 24A that receives the laser light Lh irradiated from the laser light irradiating means 22 and detects the position at which the light is received. Any device having the function of receiving the laser light Lh irradiated from the laser light irradiating means 22 and detecting the position at which the light is received can be used as the light receiving unit 24A. For example, a PSD module (light spot position detection device) equipped with a two-dimensional PSD (position detection element) for precision photometry can be used as the light receiving unit 24A. Such PSD modules (light spot position detection devices) are commercially available and easily available. In addition, for example, a one-dimensional or two-dimensional image sensor can be used as the light receiving unit 24A.

The target 24 is externally equipped with a communication device 28 that can connect to the Internet 200, and is configured so that electrical signals can be exchanged with the target 24 using a computer 30 from an office or the like away from the site. The electrical signals given to the target 24 include electrical signals regarding the power on/off of the light receiving unit 24A of the target 24, and the electrical signals sent from the target 24 to the computer 30 include electrical signals regarding the position where the light receiving unit 24A of the target 24 receives the laser light Lh (the position of the light receiving point 24A1).

The communication device 28 may be modularized and integrated into the target 24.

Next, a specific measurement method using the structure displacement measurement system 20 according to the second embodiment will be described. FIG. 8 is a side view showing a state in which a relative vertical displacement v (the difference in the vertical position coordinate of the installation position (position P2) of the target 24 on the underside of the main girder 104 relative to the installation position (position P1) of the laser light irradiation means 22 on the underside of the main girder 104) occurs at position P2, which is the installation point of the target 24 on the main girder 104 of the superstructure 102 of the bridge 100. A case in which measurement is performed using the structure displacement measurement system 20 in this state will be described. In this state, the relative vertical displacement v, which is the difference in the vertical position coordinate of the installation position P2 of the target 24 on the underside of the main girder 104 relative to the installation position P1 of the laser light irradiation means 22 on the underside of the main girder 104, is the same as the difference in the vertical position coordinate of the light receiving point 24A0 of the target 24 (light receiving point 24A0 in the reference state, which is the first time) relative to the emission point 22A1 of the laser light Lh.

In measurements using the structure displacement measurement system 20, in a state where a relative vertical displacement v has occurred (the state shown in FIG. 8 at the second time), the position coordinates of the light receiving position (light receiving point 24A1) where the light receiving unit 24A receives the laser light Lh irradiated by the laser light irradiating means 22 are measured, and the relative vertical displacement v at position P2 where the target 24 is placed is calculated from the difference between this position coordinate and the position coordinate of the light receiving position (light receiving point 24A0) in the reference state.

Specifically, first, an electrical signal (an electrical signal for turning on the power supply of the laser light irradiation means 22, and an electrical signal for causing the laser light irradiation means 22 to irradiate the laser light Lh) is input from the instruction unit 30B of the computer 30 to the laser light irradiation means 22 via the Internet 200 and the communication device 26, and the laser light irradiation means 22 irradiates the laser light Lh to the target 24.

The laser light Lh irradiated from the laser light irradiating means 22 to the target 24 is received by the light receiving section 24A of the target 24, and the light receiving point 24A1 is detected by the light receiving section 24A. The target 24 that receives the laser light Lh transmits data about the position where the laser light Lh was received (light receiving point 24A1) as an electrical signal via the communication device 28. The transmitted electrical signal is sent via the Internet 200 and is received by the displacement amount calculation section 30A of the computer 30.

The displacement amount calculation unit 30A calculates the vertical displacement v at the position P2 where the target 24 is placed from the data of the light receiving position (light receiving point 24A0) of the light receiving unit 24A in the reference state (first time) and the data of the light receiving position (light receiving point 24A1) of the light receiving unit 24A at the displacement measurement time (second time). Specifically, the displacement amount calculation unit 30A calculates the difference between the vertical position coordinate of the light receiving point 24A0 and the vertical position coordinate of the light receiving point 24A1, for example, to calculate the vertical displacement v at the position P2 where the target 24 is placed.

As described above, the structure displacement measurement system 20 according to the second embodiment is placed on the main girder 104 of the bridge 100, which is the measurement target, and is therefore capable of measuring the vertical displacement v at the position P2 described above with high accuracy. Furthermore, since it is only necessary to perform measurements at the first time and the second time, and there is no need to continue measuring at all times, the time burden of measurement is small.

In the above explanation of the structure displacement measurement system 20 according to the second embodiment, as shown in Figures 5 and 8, a case has been described in which the structure displacement measurement system 20 is installed on the underside of the main girder 104 of the superstructure 102 of the bridge 100, but the location where the structure displacement measurement system 20 according to the second embodiment can be installed is not limited to the underside of the main girder of the bridge superstructure. Furthermore, the measurement target is not limited to the difference in vertical position coordinates between two specified positions P1 and P2 of the superstructure 102 of the bridge 100.

In the structure displacement measurement system 20 according to the second embodiment, an instruction signal is input from the instruction unit 30B of the computer 30 to the laser light irradiation means 22 via the Internet 200 and the communication device 26, but an instruction signal may also be input directly from the instruction unit 30B to the laser light irradiation means 22 via a wired or wireless connection.

(3) Third embodiment FIG. 9 is a schematic bottom view of a structure displacement measurement system 40 according to a third embodiment of the present invention, FIG. 10 is a vertical cross-sectional view (a cross-sectional view cut vertically along line X-X in FIG. 9) of a superstructure 102 of a bridge 100 to which the structure displacement measurement system 40 according to the third embodiment is applied, and FIG. 11 is an enlarged vertical cross-sectional view showing an enlarged portion XI in FIG. 10.

The structure displacement measurement system 40 according to the third embodiment is a structure displacement measurement system in which a plurality of structure displacement measurement systems 20 according to the second embodiment are arranged on the underside of the main girder 104 of the superstructure 102 of the bridge 100 in the bridge axis direction of the bridge 100 when viewed from the direction perpendicular to the bridge axis of the bridge 100. The structure displacement measurement system 10 according to the first embodiment only has one set of displacement measurement means when the laser light irradiation means 12 and the reflecting member 14 irradiated with the laser light L from the laser light irradiation means 12 are considered as one set of displacement measurement means, and the structure displacement measurement system 20 according to the second embodiment also only has one set of displacement measurement means when the laser light irradiation means 22 and the target 24 irradiated with the laser light Lh from the laser light irradiation means 22 are considered as one set of displacement measurement means. In other words, the structure displacement measurement system 10 according to the first embodiment and the structure displacement measurement system 20 according to the second embodiment are structure displacement measurement systems that measure the difference in vertical position coordinates between two specific positions in the bridge superstructure 102 in a limited local range using at least one displacement measurement means, but the structure displacement measurement system 40 according to the third embodiment is a structure displacement measurement system in which multiple structure displacement measurement systems 20 according to the second embodiment, which have laser light irradiation means 22 and targets 24, are arranged in the superstructure 102 of the bridge 100 in the bridge axis direction of the bridge 100 as viewed from the direction perpendicular to the bridge axis of the bridge 100, as shown in FIG. 9, and is a structure displacement measurement system that measures the amount of displacement of the vertical component between multiple specific positions in the bridge superstructure 102 over a wide range in the bridge axis direction of the bridge 100, that is, the difference in vertical position coordinates.

The structure displacement measurement system 40 according to the third embodiment is configured as follows. That is, when the laser light emitting means 22 and the target 24 irradiated with the laser light Lh from the laser light emitting means 22 are regarded as one set of displacement measurement means 42, and the area from the laser light emitting means 22 to the target 24 included in the set of displacement measurement means 42 is regarded as one displacement measurement area 44, in the structure displacement measurement system 40 according to the third embodiment, as shown in FIG. 9, multiple sets of displacement measurement means 42 are installed on the underside of the main girder 104 of the superstructure 102 of the bridge 100, and among the respective displacement measurement areas 44 of the multiple sets of displacement measurement means 42, there is a predetermined distance between the displacement measurement areas 44 closest to each other when viewed from the direction perpendicular to the bridge axis of the bridge 100, which is the direction perpendicular to the laser light Lh irradiated from the laser light emitting means 22.

More specifically, the structure displacement measurement system 40 according to the third embodiment includes n sets of displacement measurement means 42, which are arranged in order from the first set to the nth set from the upper left of Fig. 9. The i-th set (i = 1, 2, ..., n) of the displacement measurement means 42 includes the i-th (i = 1, 2, ..., n) laser light irradiation means 22 and the i-th (i = 1, 2, ..., n) target 24.

（前記関係式３中、
Ｌ１は、１番目のレーザー光照射手段２２の配置位置と１番目のターゲット２４の配置位置との間の、測定する変位量の方向と直交する一定の方向における距離（図９では橋梁１００の橋軸方向における距離）であり、
Ｌｉは、ｉ番目のレーザー光照射手段２２の配置位置とｉ番目のターゲット２４の配置位置との間の、測定する変位量の方向と直交する一定の方向における距離（図９では橋梁１００の橋軸方向における距離）であり、
Ｍｉは、ｉ番目のターゲット２４の配置位置とｉ＋１番目のレーザー光照射手段２２の配置位置との間の、測定する変位量の方向と直交する一定の方向における距離（図９では橋梁１００の橋軸方向における距離）である） In the structure displacement measurement system 40 according to the third embodiment, when the distance between the first laser light application means 22 and the nth target 24 in a certain direction perpendicular to the direction of the displacement to be measured, that is, the distance in the bridge axis direction of the bridge 100 in Figure 9, is denoted as Sn, the following relational expression 3 holds.

(In the above Relational Formula 3,
L1 is the distance between the arrangement position of the first laser light irradiation means 22 and the arrangement position of the first target 24 in a certain direction perpendicular to the direction of the displacement to be measured (in FIG. 9 , the distance in the bridge axis direction of the bridge 100);
Li is the distance between the arrangement position of the i-th laser light irradiation means 22 and the arrangement position of the i-th target 24 in a certain direction perpendicular to the direction of the displacement to be measured (in FIG. 9 , the distance in the bridge axis direction of the bridge 100);
Mi is the distance between the arrangement position of the i-th target 24 and the arrangement position of the (i+1)-th laser light irradiation means 22 in a certain direction perpendicular to the direction of the displacement to be measured (in FIG. 9, the distance in the bridge axis direction of the bridge 100)

Therefore, by combining and analyzing the relative vertical displacements v measured by each of the multiple sets of displacement measuring means 42 in the bridge axis direction of the bridge 100, it is possible to grasp the vertical deformation state of the superstructure 102 of the bridge 100 over a wide area in the bridge axis direction of the bridge 100.

In FIG. 9, the n sets of displacement measuring means 42 (n laser light emitting means 22 and n targets 24) are arranged in a substantially straight line in the bridge axis direction of the bridge 100, but the above relational expression 3 does not necessarily have to be arranged in this way and will hold if the n sets of displacement measuring means 42 (n laser light emitting means 22 and n targets 24) are arranged so that the position coordinates are different in a certain direction perpendicular to the direction of the displacement amount to be measured.

Figure 12 is a side view of four sets of displacement measuring means 42 (n = 4) when the i-th target 24 and the i+1-th laser light emitting means 22 are arranged without any gaps so that the distance Mi in the bridge axis direction of the bridge 100 is almost zero, and shows the state in which relative vertical displacements v1, v2, v3, and v4 have occurred at positions P11, P12, P13, and P14, which are the installation points of the targets 24 on the main girder 104 of the superstructure 102 of the bridge 100, with respect to the emission point of the laser light Lh.

In the arrangement state of FIG. 12, the computer 30 calculates the vertical displacements v1, v2, v3, and v4 at each position where the target 24 is installed from the light receiving position data of the light receiving unit 24A in the reference state and the light receiving position data of the light receiving unit 24A at the time of displacement measurement, and calculates the vertical deformation state of the superstructure 102 of the bridge 100 for the area consisting of the four displacement measurement areas 44 (44a, 44b, 44c, 44d) by combining the calculated vertical displacements v1, v2, v3, and v4.

Also, for example, the first laser light irradiation means may be placed near the support at one end of the bridge girder in the bridge axis direction (one end of the entire displacement measurement area), and the nth target 24 may be placed near the support at the other end of the bridge girder in the bridge axis direction (the other end of the entire displacement measurement area), so as to cover almost the entire length of the bridge girder. By placing them in this way, for example, the vertical displacement amount (vertical displacement amount from the reference state) of the part where the kth target 24 is placed can be calculated as the sum (v1 + v2 + ... + vk) of each vertical displacement calculated by each displacement measurement means 42 (the first to kth displacement measurement means 42).

In the structure displacement measurement system 40 according to the third embodiment, n sets of displacement measurement means 42 are installed to calculate the vertical deformation state of the superstructure 102 of the bridge 100 for an area consisting of n displacement measurement areas 44. However, by installing more displacement measurement means 42 so as to cover the entire range between the supports 106 of the superstructure 102 of the bridge 100 and measuring the relative vertical displacement v for all displacement measurement areas 44, it is possible to grasp the overall vertical deformation state of the superstructure 102 of the bridge 100, as shown, for example, in FIG. 13. In FIG. 13, the reference state is indicated by a dashed line, and the state at the time of displacement measurement is indicated by a solid line.

In the arrangement state in FIG. 12, the distance Mi between the arrangement position of the i-th target 24 and the arrangement position of the i+1-th laser light irradiation means 22 is configured to be approximately zero, but as in the arrangement state in FIG. 9, the i-th target 24 and the i+1-th laser light irradiation means 22 may be arranged to leave a distance Mi (>0) between them depending on the dimensions and state of the installation position.

In such cases, the amount of displacement from the end of the bridge girder at each location can be calculated by correcting the vertical displacement measured at each location according to the interval of Mi (>0), as described above.

For example, there is a method of estimating the angle _{θ mi} between the underside of the main girder 104 at the i-th target installation position and the bridge axis direction of the bridge 100 from the angle θ i between the underside of the main girder 104 at the i-th laser light application means 22 installation position and the bridge axis direction of the bridge 100, and the angle θ i+ ₁ between the underside of the main girder 104 at the ( _i+1 )th laser light application means 22 installation position and the bridge axis direction of the bridge 100, and calculating the vertical displacement correction amount (= Mi × tan θ _mi ).

In this case, the angle θ _mi between the underside of the main girder 104 at the i-th target installation position and the bridge axis direction of the bridge 100 is calculated according to the ratio of the distances Li and Mi, for example, as follows:
θ _mi =(Li×θ _i+1 +Mi×θ _i )/(Li+Mi)
It can be calculated as follows.

The structure displacement measurement system 40 according to the third embodiment is a structure displacement measurement system in which multiple structure displacement measurement systems 20 according to the second embodiment are arranged on the underside of the main girders 104 of the superstructure 102 of the bridge 100, so the description of the structure displacement measurement system 20 according to the second embodiment itself shall be replaced with the description in "(2) Second embodiment" above (the set of displacement measurement means 42 is the same as the structure displacement measurement system 20 according to the second embodiment).

In addition, the structure displacement measurement system 40 according to the third embodiment is an embodiment that uses multiple structure displacement measurement systems 20 according to the second embodiment, but instead of the structure displacement measurement system 20 according to the second embodiment, a structure displacement measurement system may be configured using multiple structure displacement measurement systems 10 according to the first embodiment.

(4) Fourth embodiment The structure displacement measurement systems 10, 20 according to the first and second embodiments of the present invention are structure displacement measurement systems that measure the difference in vertical position coordinate between two specified positions on the superstructure 102 of a bridge 100, and the structure displacement measurement system 40 according to the third embodiment of the present invention is a structure displacement measurement system in which a plurality of structure displacement measurement systems 20 according to the second embodiment are arranged on the superstructure 102 of the bridge 100 in the bridge axis direction of the bridge 100 when viewed from the direction perpendicular to the bridge axis of the bridge 100. The structure displacement measurement systems 10, 20, 40 according to the first, second and third embodiments of the present invention are all structure displacement measurement systems that measure the difference in vertical position coordinate between a plurality of positions in the superstructure 102 of the bridge 100, but the structure displacement measurement system 50 according to the fourth embodiment of the present invention is a structure displacement measurement system that measures the difference in horizontal position coordinate between a plurality of positions in an upright structure 302 (e.g., a substructure or building of a bridge) that stands on the ground 300.

Figure 14 is a side view that shows a schematic diagram of a structure displacement measurement system 50 according to a fourth embodiment of the present invention. In Figure 14, the standing reference state (a state in which no horizontal displacement occurs in the standing structure 302) is shown by a dashed line, and the state at the time of displacement measurement is shown by a solid line.

The structure displacement measurement system 50 according to the fourth embodiment is, in brief, an embodiment in which the structure displacement measurement systems 20 and 40 according to the second and third embodiments are applied to an erect structure 302 (e.g., a bridge substructure or a building) erected on the ground 300. The structure displacement measurement system 50 according to the fourth embodiment uses a target-mounted laser light irradiation means 52 that integrates a laser light irradiation means 22 and a target 24 that receives the irradiation of the laser light Lv from the laser light irradiation means 22, and the target-mounted laser light irradiation means 52 irradiates the laser light Lv in the vertical direction. Therefore, the structure displacement measurement system 50 according to the fourth embodiment measures the difference in horizontal position coordinates between multiple positions in the erect structure 302 (e.g., a bridge substructure or a building) erected on the ground 300.

As mentioned above, the structure displacement measurement system 50 according to the fourth embodiment is, simply put, an embodiment in which the structure displacement measurement system 40 according to the second and third embodiments is applied to an erect structure 302 (e.g., a bridge substructure or a building) erected on the ground 300, so that any explanation other than the above will be replaced by the explanation of the structure displacement measurement systems 20 and 40 according to the second and third embodiments.

In FIG. 14, four target-mounted laser light irradiation means 52 are depicted, and there are three displacement measurement areas; however, there may be five or more target-mounted laser light irradiation means 52 and four or more displacement measurement areas, or there may be two or three target-mounted laser light irradiation means 52 and one or two displacement measurement areas.

In addition, in this specification, "standing on the ground" does not only mean standing on the surface of the ground, but also includes cases where the device is buried a certain length below the surface of the ground, where the device is dug into the ground and standing on the supporting foundation, or where a pile is driven into the ground and the device is standing on the pile.

(5) Fifth embodiment Fig. 15 is a side view showing a structure displacement measurement system 60 according to a fifth embodiment of the present invention. In Fig. 15, the standing reference state (a state in which no horizontal displacement occurs in the standing structure 302) is indicated by a dashed line, and the state at the time of displacement measurement is indicated by a solid line.

In the structure displacement measurement system 50 according to the fourth embodiment, the target-mounted laser light irradiation means 52 is used, which integrates the laser light irradiation means 22 and the target 24 used in the structure displacement measurement systems 20 and 40 according to the second and third embodiments. Instead of that, in the structure displacement measurement system 60 according to the fifth embodiment, the reflector-mounted laser light irradiation means 62 is used, which integrates the laser light irradiation means 12 and the reflecting member 14 used in the structure displacement measurement system 10 according to the first embodiment. The reflector-mounted laser light irradiation means 62 is equipped with an inclination sensor (not shown) and also has a function of detecting the irradiation angle (e.g., angle with respect to the horizontal plane) of the irradiated laser light L. Furthermore, the reflector-mounted laser light irradiation means 62 is equipped with a light receiving unit (not shown) that receives the reflected light R that is reflected by the reflecting part of the reflecting member and returned from the laser light L irradiated to the reflecting member of the reflector-mounted laser light irradiation means 62, and also has a function of measuring the distance to the reflecting member from the data of the returned reflected light R.

The structure displacement measurement system 60 according to the fifth embodiment uses a reflector-mounted laser light irradiation means 62 that integrates a laser light irradiation means 12 and a reflector 14 that receives the laser light L from the laser light irradiation means 12, and the reflector-mounted laser light irradiation means 62 irradiates the laser light L in the vertical direction in the erect reference state. Therefore, the structure displacement measurement system 60 according to the fifth embodiment measures the relative horizontal positional fluctuation within an erect structure 302 (e.g., a bridge substructure or a building) erected on the ground 300.

As described above, the structure displacement measurement system 60 according to the fifth embodiment is generally similar to the structure displacement measurement system 50 according to the fourth embodiment, except that a reflector-mounted laser light irradiation means 62 is used instead of the target-mounted laser light irradiation means 52 used in the structure displacement measurement system 50 according to the fourth embodiment. Also, as described above, the reflector-mounted laser light irradiation means 62 used in the structure displacement measurement system 60 according to the fifth embodiment is an integrated version of the laser light irradiation means 12 and reflector 14 used in the structure displacement measurement system 10 according to the first embodiment, so that the description of these will be used to replace the description of the structure displacement measurement system 60 according to the fifth embodiment, except for the matters described in "(5) Fifth embodiment".

In FIG. 15, four reflector-mounted laser light emitting means 62 are shown, and there are three displacement measurement regions; however, there may be five or more reflector-mounted laser light emitting means 62, and four or more displacement measurement regions, or there may be two or three reflector-mounted laser light emitting means 62, and one or two displacement measurement regions.

(6) Supplementary Note In the present invention, the traveling direction of the laser light irradiated by the laser light irradiating means toward the target or the reflecting member may be arranged so as to travel at a predetermined angle to the assumed displacement direction of a structure, or may be arranged so as to travel in a direction perpendicular to the assumed displacement direction of a structure.

To explain the "expected displacement direction" in more detail, for example, if the one structure is the superstructure of a bridge, it is expected that the superstructure will be displaced vertically due to dead load and live load, so the expected displacement direction can be the vertical direction. Also, for example, if the one structure is a bridge substructure or a building erected on the ground, it is expected that horizontal displacement will occur during an earthquake, so the expected displacement direction can be the horizontal direction.

REFERENCE SIGNS LIST 10, 20, 40, 50, 60...Structural displacement measurement system 12, 22...Laser light irradiation means 12A, 22A...Laser oscillation unit 12A1, 22A1...Oscillation point 14...Reflecting member 14A...Reflecting unit 14A1...Light receiving point (reflection point)
16, 26, 28...Communication equipment 18, 30...Computer 18A, 30A...Displacement calculation unit 18B, 30B...Indication unit 24...Target 24A...Light receiving unit 24A0...Light receiving point in reference state 24A1...Light receiving point at displacement measurement time 42...Displacement measurement means 44, 44a, 44b, 44c, 44d...Displacement measurement area 52...Target-mounted laser light emitting means 62...Reflective member-mounted laser light emitting means 100...Bridge 102...Superstructure 104...Main girder 106...Support 200...Internet 300...Ground 302...Upright structure D...Distance L, Lh, Lv...Laser light P1, P2, P11, P12, P13, P14...Position R...Reflected light v, v1, v2, v3, v4...Vertical displacement θ: Angle of the laser light L with respect to the horizontal plane

Claims (6)

A structure displacement measurement system that measures the displacement of a portion on a main girder of a bridge ,
a laser beam irradiating means having a laser oscillator for emitting a laser beam and disposed on the main beam ; and a target member having a light receiving section for receiving the laser beam emitted from the laser beam irradiating means and capable of detecting a receiving position of the laser beam, the target member being disposed on the main beam at a predetermined distance from the laser beam irradiating means in the emission direction of the laser beam emitted from the laser beam irradiating means, n pieces (n≧2) of each target member;
a laser angle adjustment means for adjusting an emission angle of the laser light emitted from each of the n laser light irradiation means to a predetermined angle;
a displacement amount calculation means for calculating a displacement amount of a vertical component of a portion on the main beam where each of the n target members is disposed based on position information regarding a light receiving position obtained by each of the light receiving units of the n target members ;
Equipped with
all of the n laser light application means are disposed on one of the main girders of the bridge, and each of the n target members is disposed on the same main girder at a predetermined distance from each of the n laser light application means in a longitudinal direction of the same main girder,
Among the n laser light irradiation means and the n target members, the k+1th (1≦k≦n-1) laser light irradiation means and the kth (1≦k≦n) target member are arranged side by side in a direction perpendicular to the bridge axis direction of the bridge on the same main girder so that a distance Mi in a certain direction perpendicular to the vertical direction of the part on the same main girder is almost zero, and among the n laser light irradiation means and the n target members, a direction from the kth (1≦k≦n) laser light irradiation means to the kth (1≦k≦n) target member is an emission direction of the laser light emitted from the kth laser light irradiation means, and a distance Sn between the 1st laser light irradiation means and the nth target member in a certain direction perpendicular to the vertical direction of the part on the same main girder is expressed by the following relational expression 1, that is,
(In the above Relational Formula 1,
L1 is a distance between the arrangement position of the first laser light irradiation means and the arrangement position of the first target member in a certain direction perpendicular to the vertical direction of a portion on the same main girder ,
Li is the distance between the arrangement position of the i-th laser light irradiation means and the arrangement position of the i-th target member in a certain direction perpendicular to the vertical direction of the portion on the same main beam ,
Mi is the distance between the position of the i-th target member and the position of the (i+1)-th laser light irradiation means in a certain direction perpendicular to the vertical direction of the portion on the same main girder .
the n laser light irradiation means and the n target members are arranged so that the n laser light irradiation means and the n target members satisfy the above condition and the distance Sn is substantially equal to the entire length of the same main beam in the longitudinal direction ,
The displacement amount calculation means calculates a difference between first position information about a light receiving position obtained when a laser beam, which is adjusted to a predetermined angle by the laser angle adjustment means and emitted from the (n-1)th laser beam irradiating means at a first time, is received by the light receiving unit of the (n-1)th target member, and second position information about a light receiving position obtained when a laser beam, which is adjusted to the predetermined angle by the laser angle adjustment means and emitted from the (n-1)th laser beam irradiating means at a second time after the first time, is received by the light receiving unit of the (n-1)th target member, based on difference information between first position information about a light receiving position obtained when a laser beam, which is adjusted to the predetermined angle by the laser angle adjustment means and emitted from the (n-1)th laser beam irradiating means at a second time after the first time, is received by the light receiving unit of the (n-1)th target member. ) a structural displacement amount can be calculated, and an nth structural displacement amount from the first time to the second time of a portion on the main girder on which the nth target member is disposed can be calculated based on difference information between first position information about a light receiving position obtained when the laser light emitted from the nth laser light irradiating means after being adjusted to a predetermined angle by the laser angle adjustment means at the first time is received by the light receiving unit of the nth target member, and second position information about a light receiving position obtained when the laser light emitted from the nth laser light irradiating means after being adjusted to the predetermined angle by the laser angle adjustment means at a second time after the first time is received by the light receiving unit of the nth target member ,
A structural displacement measurement system characterized in that the (n-1)th structural displacement amount and the nth structural displacement amount that can be calculated by the displacement amount calculation means are displacement amounts of vertical components of a portion on the same main girder on which the target member is placed . A structure displacement measurement system that measures the displacement of a portion on a main girder of a bridge ,
a laser beam irradiating means having a laser oscillator for emitting a laser beam and arranged on the main beam , a reflecting member for reflecting the laser beam, arranged on the main beam at a predetermined distance from the laser beam irradiating means in the emission direction of the laser beam emitted from the laser beam irradiating means, and n (n≧2) reflected light receiving units arranged close to each of the laser beam irradiating means on the main beam , receiving reflected light of the laser beam reflected by the reflecting member and capable of detecting the receiving position of the reflected light,
a laser angle detection means for detecting an emission angle of a laser beam emitted from each of the n laser beam irradiation means;
a displacement amount calculation means for calculating a displacement amount of a vertical component of a portion on the main beam where each of the n reflecting members is disposed, based on emission angle information of each of the laser beams emitted from the n laser beam irradiating means, which is obtained by detection using the laser angle detection means, and position information on a receiving position of the reflected light, which is obtained by each of the n reflected light receiving units;
Equipped with
the n laser light emitting means and the n reflected light receiving units are all disposed on one of the main girders of the bridge, and each of the n reflecting members is disposed on the same main girder at a predetermined distance from each of the n laser light emitting means in a longitudinal direction of the same main girder,
Among the n laser light irradiation means and the n reflecting members, the k+1th (1≦k≦n-1) laser light irradiation means and the kth (1≦k≦n) reflecting member are arranged side by side in a direction perpendicular to the bridge axis direction of the bridge on the same main girder so that the distance Mi in a certain direction perpendicular to the vertical direction of the part on the same main girder is almost zero, and the direction from the kth (1≦k≦n) laser light irradiation means to the kth (1≦k≦n) reflecting member among the n laser light irradiation means and the n reflecting members is the emission direction of the laser light emitted from the kth laser light irradiation means, and the distance Sn between the 1st laser light irradiation means and the nth reflecting member in a certain direction perpendicular to the vertical direction of the part on the same main girder is expressed by the following relational expression 2, that is,
(In the above-mentioned Relational Formula 2,
L1 is a distance between the arrangement position of the first laser light irradiation means and the arrangement position of the first reflecting member in a certain direction perpendicular to the vertical direction of a portion on the same main beam ,
Li is the distance between the position of the i-th laser light irradiation means and the position of the i-th reflection member in a certain direction perpendicular to the vertical direction of a portion on the same main beam ,
Mi is the distance between the position of the i-th reflecting member and the position of the (i+1)-th laser light irradiating means in a certain direction perpendicular to the vertical direction of the portion on the same main beam .
the n laser light irradiation means and the n reflecting members are arranged so that the n laser light irradiation means and the n reflecting members satisfy the above condition and the distance Sn is substantially equal to the entire length of the same main beam in the longitudinal direction ,
The displacement amount calculation means calculates the (n-1)th reflecting member from the portion on the main beam where the (n-1)th reflecting member is disposed based on emission angle difference information between a first emission angle obtained by detecting an emission angle of the laser light emitted from the (n-1)th laser light irradiating means at a first time with the laser angle detection means and a second emission angle obtained by detecting an emission angle of the laser light emitted from the (n-1)th laser light irradiating means at a second time after the first time with the laser angle detection means, and position information on a light receiving position obtained by the laser light emitted from the (n-1)th laser light irradiating means at the second time being reflected by the (n-1)th reflecting member and being received by the (n-1)th reflected light receiving unit. 1) a structural displacement amount can be calculated, and an nth structural displacement amount from the first time to the second time of a portion on the main beam where the nth reflecting member is arranged can be calculated based on emission angle difference information between a first emission angle obtained by detecting the emission angle of the laser light emitted from the nth laser light emitting means at the first time with the laser angle detection means and a second emission angle obtained by detecting the emission angle of the laser light emitted from the nth laser light emitting means at a second time after the first time with the laser angle detection means, and position information on a light receiving position obtained when the laser light emitted from the nth laser light emitting means at the second time is reflected by the nth reflecting member and received by the nth reflected light receiving unit ,
A structural displacement measurement system characterized in that the (n-1)th structural displacement amount and the nth structural displacement amount that can be calculated by the displacement amount calculation means are displacement amounts of vertical components of portions on the same main girder where the reflective member is arranged . 3. A structure displacement measurement system according to claim 1 , wherein a first laser light irradiation means among the n laser light irradiation means is disposed near a support of a substructure of a bridge. 2. A structural displacement measurement system according to claim 1 , wherein the laser light irradiation means and the target member are installed on the underside of the same main girder. 3. A structural displacement measurement system according to claim 2 , wherein the laser light irradiation means and the reflecting member are installed on the underside of the same main girder. 6. A structure displacement measurement system according to claim 1, wherein the displacement amount calculation means is an externally connectable computer.

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